1. Department of Psychology, Tsinghua Laboratory of Brain and Intelligence, Tsinghua University, Beijing 100084, China
2. Laboratory of Advanced Computing and Storage, Central Research Institute, 2012 Laboratories, Huawei Technologies Co. Ltd., Beijing 100084, China
3. Institute of Automation, Chinese Academy of Science, Beijing 100190, China
4. University of Chinese Academy of Science, Beijing 100049, China